Sand pressure on Buried Vessel?

Worst case is the weight of sand at depth of vessel. Consider it to be fluid. For example, if the vessel is 50 ft deep and sand is 120 lb/cu ft, then pressure on vessel is 50 X 120 = 6000 lb/sq ft or 42 psi.

Dear Bill Sir,

Thanks very much for your early reply......

However, I was thinking that, if we know the volume of box under the ground in which vessel is to be buried, we know the density of sand, so we can calculate the weight of the sand which will be filled in the box. Then, as we know the outer surface area of vessel which will be buried, we can calculate the "sand weight over the surface area of vessel" (i.e. load / area) will give us the pressure.

Am I right sir? Please correct me if I am wrong.